In devices for projecting images several beams are superimposed for each pixel and projected onto a projection screen. In doing so, in an ideal case a single spot is generated on the projection screen which is composed of the colors of the beams. Using a so called “Flying Spot Method”, the beams are directed in front of the projection screen by a movable mirror, by which via appropriate motion an image may be generated on the projection screen. Minimal angular deviations of the superimposed beams, caused by production, result in an incongruity of the single spots on the projection screen which causes color defects in the projected image. Due to thermal stress the deviation of single spots may also change during operation.